What's Rebecca Romijn's secret to keeping a smokin'-hot body? Not owning a scale.

The supermodel-turned-actress shows off her curves and shares beauty tips in the April issue of InStyle magazine (inset).

It's hard to believe, but Romijn said she had to lose weight in order to play Mystique in the "X-Men" movies. "I never step on the scale. I don't even own one, so it was awful reading in the tabloids about my weight gain: 'She ballooned from 125 pounds to 150 pounds.'

"I needed to lose around 15 pounds, but I was never worried about it, and I'm not trying to lose weight now."

The 33-year-old stunner also opened up about her engagement to actor Jerry O'Connell and life after divorce.

"We have a lot of love for each other," she said, referring to her ex, John Stamos.